Editing Least fixed point (section)

{{Short description|Smallest fixed point of a function from a poset}}
[[File:Puntos fijos.svg|thumb|150px|The function ''f''(''x'')&nbsp;=&nbsp;''x''<sup>2</sup>&nbsp;−&nbsp;4 has two fixed points, shown as the intersection with the blue line; its least one is at 1/2&nbsp;−&nbsp;{{sqrt|17}}/2.]]
In [[order theory]], a branch of [[mathematics]], the '''least fixed point''' ('''lfp''' or '''LFP''', sometimes also '''smallest fixed point''') of a [[function (mathematics)|function]] from a [[partially ordered set]] ("poset" for short)  to itself is the [[fixed point (mathematics)|fixed point]] which is less than each other fixed point, according to the order of the poset. A function need not have a least fixed point, but if it does then the least fixed point is unique.